13 ms·

1k-cycle lithium-sulfur battery could increase electric vehicle ranges

79 points by maeln 5y ago

m348e912 5y ago
As Elon would say. Send me a sample, then we'll talk.
- hobs 5y ago
  Pretty sure Elon has promised insanely more powerful batteries multiple times and not delivered.
  - shiftpgdn 5y ago
    I’d like to see a citation for that claim.
    - practice9 5y ago
      I'm not sure Elon ever claimed that. Unless poster is talking about 4680 batteries, which are going to be used in production cars in Q1 or Q2 2022. But those are 20-30% more efficient/cheap compared to the 2170 form factor
    - barney54 5y ago
      See Elon Musk's claims from Battery Day: https://www.cnet.com/roadshow/news/elon-musk-reveal-battery-range-cost-tesla-battery-day/ https://www.cnet.com/roadshow/news/elon-musk-reveal-battery-...
      - throwawaylinux 5y ago
        What exactly were Musk's claims from Battery Day? That article didn't seem to make it clear.
    - maxerickson 5y ago
      A perfect task for your Tesla humanoid robot.
  - mandmandam 5y ago
    Musk just promised self driving cars next year for the ninth year in a row. - https://futurism.com/video-elon-musk-promising-self-driving-cars https://futurism.com/video-elon-musk-promising-self-driving-...
    - edhelas 5y ago
      We're not in 2023 yet!
    - teddyh 5y ago
      “The rule is, jam to-morrow and jam yesterday—but never jam to-day.” — The White Queen, Through The Looking-Glass by Lewis Carroll (1871)
    - throwawaylinux 5y ago
      From the video, the first thing that could be called that promise was talking about the end of 2019 for a couple of years then, which he then scaled back to "quite likely" in 2021. So he promised it for a couple of years and so far he's been off by about 2 years from the first "promise" shown in that video. Talking about how 90% of highway miles could be done with driver assist is not a promise and it's not self-driving. Not sure why dishonesty is required to attack Musk, there's plenty of material available.
  - sliken 5y ago
    I'm aware of promises of improvements related to the 2170 cells, which were delivered first in model 3 allowing lower prices and range of 300+ miles. Then a rev to the model S/X allowed for range and performance increases. Before the 3 the competition claimed sure the model S is an amazing car, but can Tesla actually produce an under $50k car to reach the wider luxury market. There's a pending 4680 improvements widely expect to ship in the Texas gigafactory model Y this quarter, time will tell. I believe this is generally on the announced schedule. Am I missing something? Tesla batteries seem to be delivering on promises and experts in the area seem impressed with the Tesla battery reliability, performance, longevity, and kwh/$. Some to the point of calling Tesla a hugely successful battery company that includes various packaging for their batteries in the form of power walls, and model 3/y/x/s.
gameswithgo 5y ago
It is promising that a 5x increase is even theoretically possible. If one day even a 3x improvement became mass produceable that would be enough to make electric vehicles viable for all the use cases it isn’t currently that I can think of. Long range towing, extreme cold, track days, road trips with bikes and luggage strapped to your car etc
- codesnik 5y ago
  and aviation beyond air-taxis
  - gameswithgo 5y ago
    right!
- Keyframe 5y ago
  True, but improvement on what? There's, let's say, doubling capacity (without doubling mass), doubling performance (discharge, without fire hazard), doubling how long it can hold a charge (without doubling thermals), doubling longevity (without doubling down on hazard materials)... Just of top of my head. Chemistry is hard, looks like it. What's the average doubling of any of these factors we've seen over the years? 10-20 years?
  - derriz 5y ago
    Energy density has at least doubled in the last 20 years. See figure 8 in [1]. And it's easy to overlook the most important factor for general applications - price - where the declines are much more dramatic. People complain about the lack of progress with batteries but we've observed that EV range has doubled in 8 years. I see no reason that range wouldn't double again in the next 8 years - and I see plenty of reasons for that to happen. [1] https://pubs.rsc.org/en/content/articlehtml/2021/ee/d0ee02681f https://pubs.rsc.org/en/content/articlehtml/2021/ee/d0ee0268...
    - jillesvangurp 5y ago
jcims 5y ago
in mice.
kragen 5y ago
Kotov's lab has done a lot of brilliant stuff. It'll be interesting to see if this makes it to mass adoption; probably not this year or next, though. doi:10.1038/s41467-021-27861-w and seems to be open access cc-by. If you asked me if organic polymers could resist the growth of metal dendrites, I probably would have said no, because plastics creep like crazy, and metal dendrites are hard and sharp, so over time they will inevitably win unless they stop growing. But lithium is soft like cheese, and Kevlar's creep resistance is comparable to steel's. Maybe this is why Wang and Emre are publishing groundbreaking material science in Nature Communications and I'm not.
JulianMorrison 5y ago
I wonder if this will improve prospects for battery-electric aviation? (It might not, if it's let down by energy density, for example.)
- darksaints 5y ago
  The theoretical limits of lithium sulfur batteries are about equivalent to methanol in terms of energy density, so if it is an application where methanol is out of the question (i.e. the vast majority of commercial aviation), then this is definitely too far away from practical. Looks like it could probably get close for commuter planes though.
mhandley 5y ago
The comment about recycling the aramid fibres from bulletproof vests amuses me. Bulletproof vests seem several orders of magnitude rarer around where I live than electric cars. Doesn't really make me want to move to Michigan...
- maxerickson 5y ago
  Kevlar is used for lots of things. Did they change the link to remove a statement about vests or did you read into the statement about kevlar?
  - mhandley 5y ago
    "Along with the higher capacity, lithium-sulfur batteries have sustainability advantages over other lithium-ion batteries. Sulfur is much more abundant than the cobalt of lithium-ion electrodes. In addition, the aramid fibers of the battery membrane can be recycled from old bulletproof vests."
  - et2o 5y ago
    Look at the third-to-final paragraph where it explicitly mentions recycling Kevlar vests.
- throwaway0a5e 5y ago
  Bullet proof vests, racing harnesses, etc, etc, all sorts of safety critical fiberous stuff like that ages out long before the fibers are degrading because the manufacturers make assumptions about the lifetime of the product in chemically harsh environments (for obvious ass covering reasons) and assign it an expiration date and users are not willing to say "well I use the product in a cool dry basement so I'm sure it's fine to go 2x the expiration" and accept the responsibility themselves so these products get replaced/recycled at a very high rate. As others have stated, kevlar is also used in all sorts of other applications. The material can come from wherever.
- llampx 5y ago
  Police, security and army are probably most of the demand for bulletproof vests, and the supply of used ones.
Gareth321 5y ago
It's not such a problem right now thanks to the supply chain crunch, but there are a lot of us sitting on the sidelines waiting for EVs to achieve better mileage before making the move. Our family has only one car, and it needs to be able to do not just the daily commute (for which I acknowledge at least 90% of the kilometers on this car will be used), but also the road trips. I rented a Model 3 LR to test out how realistic these trips are in Europe, driving 1,200km to Austria for a ski trip. 1. The stated range goes down the toilet at motorway speeds. Expected range plummeted from 500km to 300km. Actual range was more like 250km, probably thanks to the cold temperatures. This was a *50%* reduction. 2. We had to plan the trip carefully around chargers. There were 10 minute detours to find chargers, traffic jams at the chargers, and slow charging speeds (probably due to said cold). We tried to charge from about 10% to 80%, but this was taking more than an hour, and shifted to 10% to 60%, which was around 40 mins. Each stop averaged 1+ hour, including the detour, waiting, and charging. 3. There were no chargers at the lodge, and this meant a final charge before ascending the mounting to near 100% to ensure that despite the extreme cold we could make it all the way up and back down. We also wanted to ensure we had extra power in case we got stuck on the road and had heat. This final stop was another hour. All up, the EV added more than *eight hours* to our round trip. Some of this time might have been spent on toilet breaks and eating anyway, but nowhere near *eight hours.* Bear in mind this was all on a near new Tesla with a near new battery and presumably the fasted possible charge rate and some of the best range available in an EV right now. This is just a huge fail for road trips, and I'm so glad I rented one to find this out before buying. I'm hopeful battery technology like this makes it into production ASAP. There is so much R&D pouring into batteries right now.
- nicoburns 5y ago
  My understanding is that solid-state lithium ion batteries (which should roughly double capacity while also being much less fire prone) are likely to be the next big thing with pretty much all major car manufacturers working on bringing them to market and the estimated timeframe being 2025-2030.
  - jabl 5y ago
    From what I've understood LFP (also much less fire prone) is poised to be the next big thing. But maybe that's more in the short term and for "budget" models.
markvdb 5y ago
If this also entails a 5x improvement in weight, let's see if that potentially enables hand luggable car batteries. - Nissan Leaf 62 kWh battery: 410 kg= 6.61 kg/kWh - order of magnitude for this type of battery: 1.32 kg/kWh - power consumption: @15 kWh/100 km - 100 km requires 15 kWh, or ~19.80 kg If something like this in order of magnitude comes true, hand luggable batteries will be able to cover non-trivial distances. Some potential consequences: - I imagine something like this could help enable a low-end, more maintainable second hand market in a not-so-distance future. - For inhabitants of terraced town houses, this could enable them to charge their batteries at home too. Hand luggable batteries could simplify _a lot_ in terms of charging infrastructure. - Exceptionally far trip? Throw in a few extra modules.
- zemvpferreira 5y ago
  That would make swapping batteries at a (previously-) gas station much more imaginable as well, and comparable to filling up a tank.
  - alias_neo 5y ago
    This was the electric car future I always envisioned. Some sort of twist-lock cylinder that one fits into one of several slots in the vehicle depending on the range they require. I'm not your how safe that would be, nor would I really want to be charging a 15kWh+ battery inside my home if I lived in a terraced house as GP suggests.
    - markvdb 5y ago
      You'd be 100% right to be wary of charging this kind of battery inside your terraced home until it has thoroughly proven itself to be fire safe. The terrace or the garden shed might provide a safe alternative though.
chris_overseas 5y ago
There's an Australian company called Li-S Energy[0] that claims to have solved the same problem a different way, using boron nanotubes. They state the theoretical limit for a lithium-sulphur battery is 2,567Wh/kg, which is around 5x that of a standard lithium-ion. [0] https://www.lis.energy https://www.lis.energy
reacharavindh 5y ago
Range anxiety is probably the only limiting factor for EVs to fully win over the oil guzzling cars. If we could use an EV with a range of about 200 KM as a daily driver with the ability to easily add on extra battery packs for the long trips, it should solve the problem nicely. Cheaper, and lighter daily driver with the flexibility to add juice when necessary. If such new battery tech makes it possible to deliver high capacity batteries with smaller lifecycles, they'd make great add on batteries. Imagine if there was a standard way to say place an extra battery pack in the trunk or the front trunk for the long trips to give an additional 400 KM range! For now, if I buy an electric car, I should simply account to pay for a rental gas car for those road trips for the sake of convenience. I'm sure many people do road trips with 45 min breaks every three hours or so, and not be anxious about availability of charging slots or even a functional charging point, but it is not for everyone.
- have_faith 5y ago
  > range anxiety is probably the only limiting factor for EVs to fully win over the oil guzzling cars For myself it's living in a 1st floor apartment, with price being secondary, and maybe concerns over the charging network in the UK at the fringes being third. I don't think range would be a big concern.
- jfk13 5y ago
  > Imagine if there was a standard way to say place an extra battery pack in the trunk or the front trunk for the long trips to give an additional 400 KM range Unfortunately, the long trips are often the trips where you really want the full luggage capacity.
foobarbecue 5y ago
I'm surprised that 1K cycles is seen as a lot.
- rthomas6 5y ago
  Well, if the range of the vehicle is 300 miles per charge, that's 300,000 miles before needing to replace the battery.
  - have_faith 5y ago
    Don't most people plug it in at home regardless of what battery is left? no one wants to leave the house on 40% battery just to run it down a "cycle". How does that effect the math?
    - sbradford26 5y ago
      It depends on the each battery chemistry but most lithium based batteries that would count as like .6 of a cycle or less. Those 1000 cycles are usually determined by full discharge and recharge which is the most demanding on the battery. Usually in the data sheet for batteries you can see cycles for full discharges and partial discharges.
    - sliken 5y ago
      Range anxiety decreases with ownership. Once you adapt to a 300 mile range you figure out what your daily usage is, and typically it's a small fraction of the range. After all who drives 5 hours per day on average? So it's not a big deal to let you car go a few days, even 40% is 120 miles, or 2 ish hours for most driving patterns. Additionally charge cycles generally means full charges, so 1000 full charges = 10,000 charge of 10%. Similar rules apply to any similar battery technology, like in an apple laptop or pretty much any cell phone. For more data points check out: https://electrek.co/2020/06/06/tesla-battery-degradation-replacement/ https://electrek.co/2020/06/06/tesla-battery-degradation-rep... From what I can tell various improvements in battery management and chemistry things have improved things since the above post.
- 5y ago
rootusrootus 5y ago
I won't lie, I'm looking forward to greater range. I've had a Model 3 (Performance trim, though, for which range is not a feature to brag about). My wife drives a Bolt. Neither car is/was capable of making a trip to grandma's house and back without a stop at a DC fast charging station. It's a day trip for us, 315 miles round trip, and setting aside 45-60 minutes for a pit stop has a significant impact. I want an EV that can pull off this 315 mile trip without dipping into reserves, even in the winter. I expect we'll get there in a few years, and I'm willing to pay a bit extra for that battery.
- sliken 5y ago
  Can't plug in for a few hours are Grandama's? Even 3-4 hours @ 4mph (120v) can make a difference. Do you set a departure time so the car and batteries are at the optimal temperature? If you charge under 25% I'd expect to charge at 550 miles per hour at a supercharger (again nav there so the car knows to arrive at optimal temperatures), so if you charge around 275 miles I'd expect another 100 miles in 10-11 minutes. If it's bitterly cold I'd expect another 10 minutes or so. Shouldn't take anywhere near 45-60 minutes unless something is seriously wrong.

79 points by maeln 5y ago

m348e912 5y ago

As Elon would say. Send me a sample, then we'll talk.

hobs 5y ago
Pretty sure Elon has promised insanely more powerful batteries multiple times and not delivered.
- shiftpgdn 5y ago
  I’d like to see a citation for that claim.
  - practice9 5y ago
    I'm not sure Elon ever claimed that. Unless poster is talking about 4680 batteries, which are going to be used in production cars in Q1 or Q2 2022. But those are 20-30% more efficient/cheap compared to the 2170 form factor
  - barney54 5y ago
    See Elon Musk's claims from Battery Day: https://www.cnet.com/roadshow/news/elon-musk-reveal-battery-range-cost-tesla-battery-day/ https://www.cnet.com/roadshow/news/elon-musk-reveal-battery-...
    - throwawaylinux 5y ago
      What exactly were Musk's claims from Battery Day? That article didn't seem to make it clear.
  - maxerickson 5y ago
    A perfect task for your Tesla humanoid robot.
- mandmandam 5y ago
  Musk just promised self driving cars next year for the ninth year in a row. - https://futurism.com/video-elon-musk-promising-self-driving-cars https://futurism.com/video-elon-musk-promising-self-driving-...
  - edhelas 5y ago
    We're not in 2023 yet!
  - teddyh 5y ago
    “The rule is, jam to-morrow and jam yesterday—but never jam to-day.” — The White Queen, Through The Looking-Glass by Lewis Carroll (1871)
  - throwawaylinux 5y ago
    From the video, the first thing that could be called that promise was talking about the end of 2019 for a couple of years then, which he then scaled back to "quite likely" in 2021. So he promised it for a couple of years and so far he's been off by about 2 years from the first "promise" shown in that video. Talking about how 90% of highway miles could be done with driver assist is not a promise and it's not self-driving. Not sure why dishonesty is required to attack Musk, there's plenty of material available.
- sliken 5y ago
  I'm aware of promises of improvements related to the 2170 cells, which were delivered first in model 3 allowing lower prices and range of 300+ miles. Then a rev to the model S/X allowed for range and performance increases. Before the 3 the competition claimed sure the model S is an amazing car, but can Tesla actually produce an under $50k car to reach the wider luxury market. There's a pending 4680 improvements widely expect to ship in the Texas gigafactory model Y this quarter, time will tell. I believe this is generally on the announced schedule. Am I missing something? Tesla batteries seem to be delivering on promises and experts in the area seem impressed with the Tesla battery reliability, performance, longevity, and kwh/$. Some to the point of calling Tesla a hugely successful battery company that includes various packaging for their batteries in the form of power walls, and model 3/y/x/s.

gameswithgo 5y ago

It is promising that a 5x increase is even theoretically possible. If one day even a 3x improvement became mass produceable that would be enough to make electric vehicles viable for all the use cases it isn’t currently that I can think of. Long range towing, extreme cold, track days, road trips with bikes and luggage strapped to your car etc

codesnik 5y ago
and aviation beyond air-taxis
- gameswithgo 5y ago
  right!
Keyframe 5y ago
True, but improvement on what? There's, let's say, doubling capacity (without doubling mass), doubling performance (discharge, without fire hazard), doubling how long it can hold a charge (without doubling thermals), doubling longevity (without doubling down on hazard materials)... Just of top of my head. Chemistry is hard, looks like it. What's the average doubling of any of these factors we've seen over the years? 10-20 years?
- derriz 5y ago
  Energy density has at least doubled in the last 20 years. See figure 8 in [1]. And it's easy to overlook the most important factor for general applications - price - where the declines are much more dramatic. People complain about the lack of progress with batteries but we've observed that EV range has doubled in 8 years. I see no reason that range wouldn't double again in the next 8 years - and I see plenty of reasons for that to happen. [1] https://pubs.rsc.org/en/content/articlehtml/2021/ee/d0ee02681f https://pubs.rsc.org/en/content/articlehtml/2021/ee/d0ee0268...
  - jillesvangurp 5y ago

jcims 5y ago

in mice.

kragen 5y ago

Kotov's lab has done a lot of brilliant stuff. It'll be interesting to see if this makes it to mass adoption; probably not this year or next, though. doi:10.1038/s41467-021-27861-w and seems to be open access cc-by. If you asked me if organic polymers could resist the growth of metal dendrites, I probably would have said no, because plastics creep like crazy, and metal dendrites are hard and sharp, so over time they will inevitably win unless they stop growing. But lithium is soft like cheese, and Kevlar's creep resistance is comparable to steel's. Maybe this is why Wang and Emre are publishing groundbreaking material science in Nature Communications and I'm not.

JulianMorrison 5y ago

I wonder if this will improve prospects for battery-electric aviation? (It might not, if it's let down by energy density, for example.)

darksaints 5y ago
The theoretical limits of lithium sulfur batteries are about equivalent to methanol in terms of energy density, so if it is an application where methanol is out of the question (i.e. the vast majority of commercial aviation), then this is definitely too far away from practical. Looks like it could probably get close for commuter planes though.

mhandley 5y ago

The comment about recycling the aramid fibres from bulletproof vests amuses me. Bulletproof vests seem several orders of magnitude rarer around where I live than electric cars. Doesn't really make me want to move to Michigan...

maxerickson 5y ago
Kevlar is used for lots of things. Did they change the link to remove a statement about vests or did you read into the statement about kevlar?
- mhandley 5y ago
  "Along with the higher capacity, lithium-sulfur batteries have sustainability advantages over other lithium-ion batteries. Sulfur is much more abundant than the cobalt of lithium-ion electrodes. In addition, the aramid fibers of the battery membrane can be recycled from old bulletproof vests."
- et2o 5y ago
  Look at the third-to-final paragraph where it explicitly mentions recycling Kevlar vests.
throwaway0a5e 5y ago
Bullet proof vests, racing harnesses, etc, etc, all sorts of safety critical fiberous stuff like that ages out long before the fibers are degrading because the manufacturers make assumptions about the lifetime of the product in chemically harsh environments (for obvious ass covering reasons) and assign it an expiration date and users are not willing to say "well I use the product in a cool dry basement so I'm sure it's fine to go 2x the expiration" and accept the responsibility themselves so these products get replaced/recycled at a very high rate. As others have stated, kevlar is also used in all sorts of other applications. The material can come from wherever.
llampx 5y ago
Police, security and army are probably most of the demand for bulletproof vests, and the supply of used ones.

Gareth321 5y ago

It's not such a problem right now thanks to the supply chain crunch, but there are a lot of us sitting on the sidelines waiting for EVs to achieve better mileage before making the move. Our family has only one car, and it needs to be able to do not just the daily commute (for which I acknowledge at least 90% of the kilometers on this car will be used), but also the road trips. I rented a Model 3 LR to test out how realistic these trips are in Europe, driving 1,200km to Austria for a ski trip. 1. The stated range goes down the toilet at motorway speeds. Expected range plummeted from 500km to 300km. Actual range was more like 250km, probably thanks to the cold temperatures. This was a *50%* reduction. 2. We had to plan the trip carefully around chargers. There were 10 minute detours to find chargers, traffic jams at the chargers, and slow charging speeds (probably due to said cold). We tried to charge from about 10% to 80%, but this was taking more than an hour, and shifted to 10% to 60%, which was around 40 mins. Each stop averaged 1+ hour, including the detour, waiting, and charging. 3. There were no chargers at the lodge, and this meant a final charge before ascending the mounting to near 100% to ensure that despite the extreme cold we could make it all the way up and back down. We also wanted to ensure we had extra power in case we got stuck on the road and had heat. This final stop was another hour. All up, the EV added more than *eight hours* to our round trip. Some of this time might have been spent on toilet breaks and eating anyway, but nowhere near *eight hours.* Bear in mind this was all on a near new Tesla with a near new battery and presumably the fasted possible charge rate and some of the best range available in an EV right now. This is just a huge fail for road trips, and I'm so glad I rented one to find this out before buying. I'm hopeful battery technology like this makes it into production ASAP. There is so much R&D pouring into batteries right now.

nicoburns 5y ago
My understanding is that solid-state lithium ion batteries (which should roughly double capacity while also being much less fire prone) are likely to be the next big thing with pretty much all major car manufacturers working on bringing them to market and the estimated timeframe being 2025-2030.
- jabl 5y ago
  From what I've understood LFP (also much less fire prone) is poised to be the next big thing. But maybe that's more in the short term and for "budget" models.

markvdb 5y ago

If this also entails a 5x improvement in weight, let's see if that potentially enables hand luggable car batteries. - Nissan Leaf 62 kWh battery: 410 kg= 6.61 kg/kWh - order of magnitude for this type of battery: 1.32 kg/kWh - power consumption: @15 kWh/100 km - 100 km requires 15 kWh, or ~19.80 kg If something like this in order of magnitude comes true, hand luggable batteries will be able to cover non-trivial distances. Some potential consequences: - I imagine something like this could help enable a low-end, more maintainable second hand market in a not-so-distance future. - For inhabitants of terraced town houses, this could enable them to charge their batteries at home too. Hand luggable batteries could simplify _a lot_ in terms of charging infrastructure. - Exceptionally far trip? Throw in a few extra modules.

zemvpferreira 5y ago
That would make swapping batteries at a (previously-) gas station much more imaginable as well, and comparable to filling up a tank.
- alias_neo 5y ago
  This was the electric car future I always envisioned. Some sort of twist-lock cylinder that one fits into one of several slots in the vehicle depending on the range they require. I'm not your how safe that would be, nor would I really want to be charging a 15kWh+ battery inside my home if I lived in a terraced house as GP suggests.
  - markvdb 5y ago
    You'd be 100% right to be wary of charging this kind of battery inside your terraced home until it has thoroughly proven itself to be fire safe. The terrace or the garden shed might provide a safe alternative though.

chris_overseas 5y ago

There's an Australian company called Li-S Energy[0] that claims to have solved the same problem a different way, using boron nanotubes. They state the theoretical limit for a lithium-sulphur battery is 2,567Wh/kg, which is around 5x that of a standard lithium-ion. [0] https://www.lis.energy https://www.lis.energy

reacharavindh 5y ago

Range anxiety is probably the only limiting factor for EVs to fully win over the oil guzzling cars. If we could use an EV with a range of about 200 KM as a daily driver with the ability to easily add on extra battery packs for the long trips, it should solve the problem nicely. Cheaper, and lighter daily driver with the flexibility to add juice when necessary. If such new battery tech makes it possible to deliver high capacity batteries with smaller lifecycles, they'd make great add on batteries. Imagine if there was a standard way to say place an extra battery pack in the trunk or the front trunk for the long trips to give an additional 400 KM range! For now, if I buy an electric car, I should simply account to pay for a rental gas car for those road trips for the sake of convenience. I'm sure many people do road trips with 45 min breaks every three hours or so, and not be anxious about availability of charging slots or even a functional charging point, but it is not for everyone.

have_faith 5y ago
> range anxiety is probably the only limiting factor for EVs to fully win over the oil guzzling cars For myself it's living in a 1st floor apartment, with price being secondary, and maybe concerns over the charging network in the UK at the fringes being third. I don't think range would be a big concern.
jfk13 5y ago
> Imagine if there was a standard way to say place an extra battery pack in the trunk or the front trunk for the long trips to give an additional 400 KM range Unfortunately, the long trips are often the trips where you really want the full luggage capacity.

foobarbecue 5y ago

I'm surprised that 1K cycles is seen as a lot.

rthomas6 5y ago
Well, if the range of the vehicle is 300 miles per charge, that's 300,000 miles before needing to replace the battery.
- have_faith 5y ago
  Don't most people plug it in at home regardless of what battery is left? no one wants to leave the house on 40% battery just to run it down a "cycle". How does that effect the math?
  - sbradford26 5y ago
    It depends on the each battery chemistry but most lithium based batteries that would count as like .6 of a cycle or less. Those 1000 cycles are usually determined by full discharge and recharge which is the most demanding on the battery. Usually in the data sheet for batteries you can see cycles for full discharges and partial discharges.
  - sliken 5y ago
    Range anxiety decreases with ownership. Once you adapt to a 300 mile range you figure out what your daily usage is, and typically it's a small fraction of the range. After all who drives 5 hours per day on average? So it's not a big deal to let you car go a few days, even 40% is 120 miles, or 2 ish hours for most driving patterns. Additionally charge cycles generally means full charges, so 1000 full charges = 10,000 charge of 10%. Similar rules apply to any similar battery technology, like in an apple laptop or pretty much any cell phone. For more data points check out: https://electrek.co/2020/06/06/tesla-battery-degradation-replacement/ https://electrek.co/2020/06/06/tesla-battery-degradation-rep... From what I can tell various improvements in battery management and chemistry things have improved things since the above post.
5y ago

rootusrootus 5y ago

I won't lie, I'm looking forward to greater range. I've had a Model 3 (Performance trim, though, for which range is not a feature to brag about). My wife drives a Bolt. Neither car is/was capable of making a trip to grandma's house and back without a stop at a DC fast charging station. It's a day trip for us, 315 miles round trip, and setting aside 45-60 minutes for a pit stop has a significant impact. I want an EV that can pull off this 315 mile trip without dipping into reserves, even in the winter. I expect we'll get there in a few years, and I'm willing to pay a bit extra for that battery.

sliken 5y ago
Can't plug in for a few hours are Grandama's? Even 3-4 hours @ 4mph (120v) can make a difference. Do you set a departure time so the car and batteries are at the optimal temperature? If you charge under 25% I'd expect to charge at 550 miles per hour at a supercharger (again nav there so the car knows to arrive at optimal temperatures), so if you charge around 275 miles I'd expect another 100 miles in 10-11 minutes. If it's bitterly cold I'd expect another 10 minutes or so. Shouldn't take anywhere near 45-60 minutes unless something is seriously wrong.